Here we import our data and make some summary plots.
EEG Data
Importing the primary EEG data set. This is odd-harmonic filtered data from region-of-interest consisting of six electrodes over occipital cortex.
We now import the data. We have three variables: wallpaper group (wg), subject, and root-mean-squared amplitude (rms).
## Observations: 400
## Variables: 3
## $ wg <chr> "P2", "PM", "PG", "CM", "PMM", "PMG", "PGG", "CMM", "P4"…
## $ subject <chr> "s01", "s01", "s01", "s01", "s01", "s01", "s01", "s01", …
## $ rms <dbl> 0.4013, 0.6555, 0.5547, 0.7635, 0.9185, 0.7285, 0.4320, …
If we plot the distribution of rms, we can clearly see that it is skewed. Furthermore, as negative rms amplitudes are impossible we will use a lognormal distribution to model these data.
The table below shows how many groups per participant we have data for.
|
subject
|
count
|
|
s01
|
16
|
|
s02
|
16
|
|
s03
|
16
|
|
s04
|
16
|
|
s05
|
16
|
|
s06
|
16
|
|
s07
|
16
|
|
s08
|
16
|
|
s09
|
16
|
|
s10
|
16
|
|
s11
|
16
|
|
s12
|
16
|
|
s13
|
16
|
|
s14
|
16
|
|
s15
|
16
|
|
s16
|
16
|
|
s17
|
16
|
|
s18
|
16
|
|
s19
|
16
|
|
s20
|
16
|
|
s21
|
16
|
|
s22
|
16
|
|
s23
|
16
|
|
s24
|
16
|
|
s25
|
16
|
Threshold Data
Here we import that data and select the columns that we’re interested in. Threshold gives the required display duration (in seconds) for the two stimuli to allow for accurate discrimination.
## Observations: 186
## Variables: 3
## $ subject <chr> "person10", "person10", "person10", "person10", "perso…
## $ wg <chr> "CM", "CMM", "P2", "P3", "P31M", "P3M1", "P4", "P4G", …
## $ threshold <dbl> 0.74125, 0.20216, 0.47697, 0.35012, 0.24529, 0.19022, …
As above, a summary of the data. And again, we have a skewed distribution, (with negative display durations being impossible), so we will use also use a lognormal distribution to model the behaviour data.
The table below shows how many groups per participant we have data for.
|
subject
|
count
|
|
person0
|
15
|
|
person10
|
16
|
|
person12
|
16
|
|
person13
|
16
|
|
person14
|
16
|
|
person15
|
16
|
|
person16
|
16
|
|
person2
|
12
|
|
person3
|
15
|
|
person4
|
16
|
|
person55
|
16
|
|
person6
|
16
|
Control Data
In addition to the primary EEG data set, we are also importing two control data sets which are (a) even harmonic data from the same occipital electrodes, and (b) odd harmonic data from six parietal electrodes (see Figure 1.1 and the main paper).